Ramirez ZR, Volpe N, Bertelli E, et al. - The present study was performed to explore the position of the conus medullaris (CM) at the first trimester 3D ultrasound in a cohort of structurally normal fetuses. Researchers designed a multicenter prospective study including a consecutive series of structurally normal fetuses between 11 and 13 weeks of gestation (CRL between 45 and 84 mm). The results showed that the assessment of the CM position is feasible at the first trimester 3D ultrasound with a good interobserver agreement in normal fetuses. It was shown that CM level was never found below the fetal umbilical cord insertion, while the CMCd was noted to increase according to the gestational age, confirming the “ascension” of the CM during fetal life.